In order to achieve better channel utilization and increase overall performance, multiple transmission and multiple reception antennas (also commonly referred to as multiple input, multiple output (MIMO)) at both evolved Node B (eNB) (or base station (BS), Node B (NB), communications controller, and the like) and User Equipment (UE) (or mobile station (MS), terminal, user, subscriber, subscriber equipment, mobile device, and the like) are considered.
An extension to MIMO makes use of multiple communications points (each of which may be a set of geographically co-located transmit or receive antennas) to transmit to or receive from a single UE or a group of UEs. As an example, the transmissions from the multiple transmission points may occur at the same time and/or the same frequency, or they may occur at different times and/or at different frequencies so that the UE (or the group of UEs) will receive transmissions from all of the multiple transmission points over a time window. This operating mode may often be referred to as multiple point transmission. As an example, at a first time, a first transmission point may transmit to a UE, at a second time, a second transmission point may transmit to the UE, and so on. Here the second time may or may not be the same as the first time.
Similarly, receptions from a single transmission point may occur at the same time and/or the same frequency, or they may occur at different times and/or at different frequencies so that multiple reception points will receive the transmissions from the transmission point over a time window. This operation mode may often be referred to as multiple point reception. As an example, at a first time, the transmission point may transmit to a first eNB, at a second time, the transmission point may transmit to a second eNB, and so on. Here, the second time may or may not be the same as the first time.
Coordinated multiple point (CoMP) reception is one form of multiple point reception, wherein the receptions of the transmissions made by the transmission point are coordinated so that the reception points may be able to either combine the multiple receptions from the transmission point or avoid interference to improve overall performance. A reception point may be an eNB, a part of an eNB (e.g., a cell), a remote radio head (RRH) connected to an eNB, and the like. It is noted that sectors of the same site, e.g., an eNB, correspond to different reception points.
CoMP transmission and reception is being considered for inclusion in next generation wireless communications systems, such as in Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) Advanced standards compliant communications systems, as a tool to improve the coverage of high data rates, to improve cell-edge throughput, and/or to increase overall communications system throughput in both high load and low load scenarios.